Method of tensioning strap and tool therefor



Oct; 24, 1967 J. R. BEACH 3,343,584

METHOD OF TENSION'ING STRAP AND TOOL THEREFOR Filed April 2, 1965 2 Sheets-Sheet 1 //v VENTOR.

jhg dC' A TTORNEYS.

0 t.24,19s7 J. R. BEACH I 3,348,584

METHOD-OF TENSIONING STRAP AND TOOL THEREFOR Filed April 2, l965 2 Sheets-Sheet 2 lNVE/VTOR. Jfiy/ @i gac- 3% W WMM/fX" ATTORNEYS.

United States Patent 3,348,584 METHOD OF TENSIONING STRAP AND TOOL THEREFOR John R. Beach, Elmhurst, Ill., assignor to Signode Corporation, a corporation of Delaware Filed Apr. 2, 1965, Ser. No. 445,224 17 Claims. (Cl. 140-932) ABSTRACT OF THE DISCLOSURE A strap tensioning tool is disclosed for drawing a plastic strap through a wire buckle for pulling tension on a loop of the strap that is 'held by the buckle, the tool comprising spring-biased, pivotally interconnected plierslike arms each provided with a pair of separate jaws to mate with corresponding jaws on the other arm, thereby defining two sets of mating jaws for gripping regions of one strap end that flank the retainer to be in generally overlapping spaced apart relation. When the jaws are engaged on the strap, one arm is operated like a lever to fulcrum the tool against the strap and apply a force couple that draws an increment of strap through the buckle. The arms of the tool have cooperating shear edges for severing the strap end after tensioning.

The instant invention relates to strap tensioning and, particularly, to a method of accomplishing same and a manually operable tool that can :be used for practicing the method. Specifically, the apparatus portion of this invention relates to a manually operable tool which is adapted to tighten or tension a strap loop having opposite end portions threaded through a buckle or similar strap retaining device.

As used in this specification, and the claims thereof, the terms strap and strapping are intended to be inclusive of all ligatures, regardless of shape, which are adapted to be tightened or tensioned by the tool embodying the instant invention.

Certain wrappings and other things requiring securance together are adapted to be held together or secured by a strap or strapping, the opposite ends of which are connected, fastened or adjustably held in a buckle, or similar fastener.

Straps which are especially suited for use with buckle type fasteners are fabricated from plastic materials such as polypropylene or nylon which, among other characteristics, possess high (1) ductility, (2) surfaces smoothness, and (3) elasticity or stretchability. The ductility permits surface conformation of the strapping. The smoothness tends to minimize resistance to sliding of the strap under tensioning force; and the elasticity insures more intimate binding of the strap and object secured thereby.

A conventional or ordinary buckle that is or can be used for fastening strapping of the character described is provided with spaced pairs of parallel bars. A strap end is threaded or woven through each pair of bars.

Ideally, the strap ends are pulled through the buckle to tension the strap until the strap loop is in snug engagement with the package or object being tied. However, the buckle is designed to mechanically trap and frictionally hold the opposite end of the tensioned strap. Therefore, notwithstanding the smooth strap surface, which would normally allow the'opposite ends to be manually pulled to partially tension the strap, a resistance to the tensioning develops in the buckle at its positions of contact and engagement with the partially stretched or tensioned strap. A resistance, greater than manual force, is generally built up or generated prior to tensioning of the strap to the desired extent. Therefore, to further tension or pull the strap, a mechanical assist must be provided.

The instant invention is concerned with the method of advancing strap through a trap retaining device and a 5 particular tool which can practice this method. The tool disclosed herein functions to augment the manual force applied thereto in tensioning of straps held :by buckles, and the like. Other tools can be used to practice this method.

Tools embodying the instant invention are adapted to grip one strap end at intraloop and extraloop regions that flank the buckle and are operative to develop a mechanical advantage of suflicient value to permit tensioning of a strap to the extent desired. v

A tool forming an exemplary embodiment of the invention has an elongated body at the opposite ends of which there are a hand grip and a pair of fixed jaws between which there is rockable a clamp which is spring biased to an open position with respect to the fixed jaws. The clamp is provided with an integral lever or handle which extends in superposed relationship to the hand grip whereby the hand grip and the lever can be squeezed to rock the clamp to a closed position wherein it establishes a double bite with respect to the fixed jaws;

The mechanism of the tool is so arranged that in one direction of movement it increases the pull or tensioning on a strap and is releasable to take repeated :bites and successively draw the strap to desired tension.

Another feature of the invention is that the parts of the tool are arranged in such a novel combination that they are operative as part of a strap cutting tool as well as a tensioning tool.

The novel method disclosed herein is basically one in which the strap is clamped on opposite sides of a strap retaining means and a force couple is applied to advance an increment of strap through the retainer.

These and other features and advantages of the present invention will become more apparent upon consideration of the following description and appended claims, when considered in conjunction with the accompanying drawings, forming a part of this specification, in which the same reference characters or numerals refer to like or corresponding parts thoughout the several views, and in which:

FIGURE 1 is an end elevational view of a device embodying an illustrative form of the invention;

FIGURE 2 is a front elevational view of the device shown in FIGURE 1; 7

FIGURE 3 is an enlarged fragmentary front elevational view of thestrap gripping facilities of the tool;

FIGURE 4 is an enlarged fragmentary sectional view taken substantially on the line 44 of FIGURE 3;

FIGURE 5 is a related enlarged fragmentary sectional view taken on the section line 55 of FIGURE 4 and corresponding to FIGURE 3, but illustrating the fully open position of the tool;

FIGURE 6 is a view corresponding to FIGURE 5 but illustrating the fully closed position of the tool;

FIGURE 7 is a front elevational view illustrating the front end portion of the device prior to tensioning a binding strap; and

FIGURE 8 is a view similar to FIGURE 7, however, showing the device rotated after having tensioned a strap.

Referring now to the drawings, the tool is shown in its entirety in FIGURES l and 2, and it includes a pair of arms 10 and 11 interengaged adjacent corresponding ends by a swivel type fastener assembly 12 to relate the arms for pliers-like opening and closing action.

The main arm 10 comprises an elongated rigid body that may be fabricated from any suitable material, such as metal, and it is preferably formed by forging, casting, or the like. The upper end of the elongated body, as indicated at 13, serves as a hand grip and is preferably gently curved to facilitate a more efficient application of manual force to the tool. The lower end of the main arm 10 is integrally connected to the hand grip 13 through a convoluted neck 13N and functions as a strap contacting workhead. The workhead has a generally fiat main wall portion 14 which is approximately triangular in front elevation, as is apparent from FIGURES 2, 3, and 6. The workhead is provided with a pair of upper and lower integral jaws 15 and 16 extending substantially normal to the plane of the fiat wall portion, with the lower jaw 16 being shown substantially aligned with the hand grip 13 and with the upper jaw 15 being shown offset from the main line of the handle, but in a common plane with the lower jaw 16. Each of the strap gripping jaws 15 and 16 has a tapered free end 1ST and 16T and, as best illustrated in FIGURE 1, to facilitate strap insertion as will become clear presently. The triangular fiat main wall portion 14 is apertured centrally to provide a pivot hole 14H which is centered between the jaws. However, the jaws present fiat strap contacting faces 15F and 16F which are directed in opposite vertical directions, but are not directly aligned. Thus, the strap contacting faces of the jaws are symmetrical about the central axis defined by the mounting hole 14H, but intersect radius lines through that axis in an oblique relation.

The other arm 11 has its upper end 17 gently curved, also to serve as a hand grip, which is located in a common plane with the hand grip 13. The lower end of the arm 11 is integrally connected to the hand grip 17 through a convoluted neck UN and functions as a plate-like clamp 18. The clamp 18 is a flat plate-like wall portion which is rockably mounted on the fastener assembly 12 which extends through the pivot hole.

As best shown in FIGURE 4, the fastener assembly 12 includes a shouldered screw 19 having a smooth shank portion 198 serving as a pivot pin mounted snug in the pivot hole 14H and extending loosely through a registering oval hole 18H (FIGURES 5 and 6) provided in a center region of the flat clamp 18. The screw shank is provided with a set of disc springs 20, a washer 21, and a locknut 22 to load the clamp 18 in snug, freely slideable relation against the fiat wall 14. The clamp 18 is also provided with a pair of complementally spaced upper and lower jaws 23 and 24, each individually associated with a corresponding one of the gripping jaws 15 and 16. The jaws 23 and 24 have tapered free ends -23T and 24T (FIGURE 1) to facilitate strap insertion.

Thus, in the preferred arrangement illustrated herein for purposes of disclosure, the clamping jaws 23 and 24 are substantially symmetrical about the pivot shank 19S and have suitably knurled, fiat strap contacting faces 23F and 24F which intersect radius lines through the pivot axis in an oblique relation. The flat, smooth surfaced facing wall portions 14 and 18 undergo relative sliding movement when the crank rocks between a jaw open position, which is illustrated in FIGURES 2, 3 and 5, and a jaw closed position, which is illustrated in FIGURE 6. Integral lugs 13L and 17L are provided on each of the arms and 11 to serve as seat posts for opposite ends of a coil spring 25 which functions as a resiliently yieldable means biasing the arms in a direction to rock the clamp 18 to a jaw open position, as illustrated in FIG- URE 2. The clamp 18 has an integral tab 18T overlapping and presenting a stop shoulder to engage an edge surface 14E (FIGURE 3) of the flat triangular wall 14 thereby defining the limit of the jaw open position at a location where the hand grips are spaced apart a convenient distance to facilitate one hand operation of the tool. Squeezing of the hand grips 13 and 17 toward each other rocks the clamp to a jaw closed position, such as is illustrated in FIGURE 6.

In the usual application of the tool for strap tensioning, the strap is fed from a supply reel (not shown) and has only one free end, and it is repeatedly required to shear the strap after each loop is formed and tensioned in order to prepare for the next operation. For this purpose, the tensioning tool has a unique arrangement wherein shearing edges 26 and 27 are located on regions of the wall portions 14 and 18, which execute an intersecting relative movement as the arms are pivoted about the pivot pin. In the illustrated embodiment, the lower edge of the flat wall portion 14 of the main arm 10 has a downwardly facing shearing edge 26, and the flat wall portion of the clamp is slotted and provided with an upwardly facing shearing edge 27. These shearing edges 26 and 27 are normally open to define a slot 28 for receiving a strap segment as illustrated in FIGURES 2 and 5, and upon squeezing of the hand grips 13 and 17, these shearing edges move in an intersecting relation to the position illustrated in FIGURE 6 for severing the strap segment.

Application of the tool for tensioning a strap loop about an object is illustrated in FIGURES 7 and 8. The strap loop 30 has its opposite ends 31 and 32 threaded through a rigid skeletal wire buckle 33. To a limited extent, the strap ends 31 and 32 can be drawn through the buckle 33 to pull slack from the strap loop, but the frictional engagement between the strap and buckle prevents development of the desired strap tautness and the tool of the present invention is provided for application to one of the strap ends to pull it through the buckle until desired tension is achieved. The tool functions somewhat on the principle of a simple lever in that it translates the force moment applied by the operator to the hand grip 13 at a mechanical advantage, which is determined by the distance A between a medial point on the hand grip 13 and the face 16F of the lower gripping jaw 16 to the distance B, which is the effective distance between the two gripping jaws 15 and 16. Therefore, relatively low manual force is applied at a relatively long lever arm and is translated into a relatively high force applied at a relatively short lever arm.

In FIGURE 7, it will be understood that the ends 31 and 32 of the strap loop have already been drawn taut manually and that the frictional action of the buckle 33 and the strap prevents full tensioning of the strap loop, at which time the tool of this invention is applied to spaced regions 32A and 32B of one strap end to provide a mechanical assist in completing the strap tensioning. The strap regions 32A and 32B are seen to flank an intermediate return bend strap portion which is frictionally engaged'by the buckle 33. As is illustrated, the lower gripping jaw 16 and its mating clamping jaw 24 engage the intraloop strap region 32A, whereas the upper gripping jaw 15 and its mating clamping jaw 23 engage the extraloop strap region 32B to dispose these strap regions in generally overlapping spaced apart relationship, this engagement being effected by squeezing the hand grips together to bring the clamp 18 into a jaw closed position against the corresponding strap regions. The hand grip 13 is then pulled to impart a clockwise rotation to the tool to move it from the FIGURE 7 position to the FIGURE 8 position and draw a segment of the engaged strap end 32 through the buckle 33. The hand grips are released to enable the spring to return the tool to the jaw open position and the jaw is repositioned to a relationship such as illustrated in FIGURE 7 to establish a bite on two corresponding intraloop and extraloop strap regions, whereupon the tool is again rotated clockwise to draw a strap segment through the buckle. This action is repeated until the strap loop is tensioned to the desired extent, and the supply end 32 of the strap may then be severed.

In the tool application illustrated in FIGURES 7 and 8, the lower jaw 16 is shown contacting the object 34 about which the strap loop is being tensioned. The strapcontacting face 16F of this lower jaw represents the point of fulcrum for the leverage action and the action of the tool for developing this fulcruming effect at the lower jaw region does not depend upon contact with the object being tied. In many instances the tool may be oriented in spaced relation from the object being tied and rotated in space with the required fulcruming and mechanical advantage effects still being achieved.

It should be noted that while FIGURE 8 may be pictured as representing the final relationship when full tension is achieved, the fact that the strap is spaced from the object being tied does not mean that slack remains in the tensioned loop. The elasticity of the strap 30 snaps the loop intimately against the object upon removal of the tool.

The broad concept of this invention has been described and illustrated in relation to a hand tool construction. However, the invention broadly contemplates relatively movable elements cooperating to provide a pair of releasable clamping means to engage spaced strap portions located on opposite sides of and movably gripped by a strap retainer. The clamping means are spaced apart on the movable elements to facilitate application of a force couple to the space-d strap portions to advance the strap through the retainer. The principle of utilizing a pair of clamping means in this relationship and for this purpose is also contemplated for use in semi-automatic and automatic strapping equipment.

The invention further contemplates a tensioning method wherein clamping engagement is applied to the spaced strap portions in any fashion to enable a force couple to be applied through such clamping engagement to the strap portions to advance an increment of strap through the retainer. This is repeated by releasing the strap and re-establishing clamping engagement to advance another increment of strap through the retainer. For example, the tool can be released and the strap clamped at two different but similarly spaced strap regions, or one of the jaws retained in its existing position and the other jaw moved to a second position. In the latter situation, the upper jaw could remain relatively stationary and the lower jaw moved relative thereto, or the lower jaw held relatively stationary and the upper jaw moved to a second gripping position.

While it is preferred that the spring 25 normally act to bias the arms towards a jaw open position and that squeezing of the tool arms is employed for rocking the clamp 18 to a jaw closed position, this relationship may be reversed if desired such that a spring could be used to bias the tool to a jaw closed position and the arms could be squeezed to achieve a jaw open position.

Thus, while various features of the invention are embodied in the structure illustrated herein, it is to be understood that changes and variations may be made by those skilled in the art without departing from the spirit and scope of the appended claims.

I claim:

1. A tool for tensioning a strap loop having opposite strap ends movably threaded through a buckle, said tool comprising an elongated rigid body having a hand grip portion at one end for application or manual force and having a pair of spaced gripping jaws mounted at the other end to engage spaced regions of one of said strap ends at locations flanking the buckle for drawing said one strap end through the buckle by fulcruming the remote one of said jaws against the strap to translate the applied force moment with a mechanical advantage determined substantially by the ratio of the distance between the hand grip portion and the remote one of said gripping jaws to the distance between said gripping jaws, a clamp rockable on said other end of said body to swing between an open position and a closed position and having a pair of complementally spaced jaws, each individually associated with a separate one of said gripping jaws, said clamping jaws being concurrently cooperable with the gripping jaws to pinch each of the said spaced strap regions when the clamp is in closed position and to release the strap when the clamp is in open position, resiliently yieldable means reacting between said body and clamp normally to bias said clamp to one of said positions, and

6. means for rocking said clamp to the other of said positions.

2. A tool for tensioning a strap loop having opposite strap ends movably threaded through a buckle, said tool comprising an elongated rigid body having a hand grip portion at one end for application of manual force and having a pair of spaced gripping jaws mounted at the other end to engage spaced regions of one of said strap ends at location flanking the :buckle for drawing said one strap end through the buckle by fulcruming the remote one of said jaws against the strap to translate the applied force with a mechanical advantage determined substantially by the ratio of the distance between the hand grip portion and the remote one of said gripping jaws to the distance between said gripping jaws, a clamp rockable on said other end of said body to swing between an open position and a closed position and having a pair of complementally spaced jaws, each individually associated with a separate one of said gripping jaws, said clamping jaws being concurrently cooperable with the gripping jaws to pinch each of the said spaced strap regions when the clamp is in closed position and to release the strap when the clamp is in open position, and re siliently yieldable means reacting between said body and clamp normally to bias said clamp to one of said positions, said clamp having a rigid handle connected thereto and operable for rocking said clamp to the other of said positions to cooperate with the resiliently yieldable means in enabling repeated gripping and release of the strap end to be drawn through the buckle.

3. A tool for tensioning a strap loop having opposite strap ends movably threaded through a buckle, said tool comprising an elongated rigid body having a hand grip portion at one end for application of manual force and having a pair of spaced gripping jaws mounted at the other end to engage spaced regions of one of said strap ends at locations flanking the buckle for drawin said one strap end through the buckle by fulcruming the remote one of said jaws against the strap to translate the applied force moment with a mechanical advantage determined substantially by the ratio of the distance between the hand grip portion and the remote one of said gripping jaws to the distance between said gripping jaws, a clamp rockable on said other end of said body to swing between an open position and a closed position and having a pair of complementally spaced jaws, each individually associated with a separate one of said gripping jaws, said clamping jaws being concurrently cooperable with the gripping jaws to pinch each of the said spaced strap regions when the clamp is in closed position and to release the strap when the clamp is in open position, resiliently yieldable means reacting between said body and clamp normally to bias said clamp to one of said positions, and manually operable lever means rigidly connected to said clamp for rocking the same to the other of said positions, said clamp and said body member having corresponding smooth surfaced portions undergoing flush faced sliding contact during rocking movement of the clamp, the last named portions having cooperating shearing edges extending transversely of the direction of sliding movement and defining a slot to receive a strap portion and sever the same by operating the lever means to rock said clamp to said other position.

4. A tool for tensioning a strap loop having opposite strap ends movably threaded through a buckle, said tool comprising an elongated rigid body having a hand grip portion at one end for application of manual force and having a pair of spaced gripping jaws mounted at the other end to engage spaced regions of one of said strap ends at locations flanking the buckle, with the ratio of the distance between the hand grip portion and the remote one of said gripping jaws to the distance between said gripping jaws substantially determining the mechanical advantage provided by the tool, a clamp rockable on 7 said other end of said body to swing between an open position and a closed position and having a pair of complementally spaced jaws, each individually associated with a separate one of said gripping jaws, said clamping jaws being concurrently cooperable with the grippin aws to pinch each of the said spaced strap regions when the clamp is in closed position and to release the strap when the clamp is in open position, resiliently yieldable means reacting between said body and clamp normally to bias said clamp to said open position, and means for rocking said clamp to closed position.

5. A tool for tensioning a strap loop having opposite strap ends movably threaded through a buckle, said tool comprising an elongated rigid body having a hand grip portion at one end for application of manual force and having a pair of spaced gripping jaws mounted at the other end to engage spaced regions of one of said strap ends at locations flanking the buckle, with the ratio of the distance between the hand grip portion and the remote one of said gripping jaws to the distance between said gripping jaws substantially determining the mechanical advantage provided by the tool, a clamp rockable on said other end of said body to swing between an open position and a closed position, said clamp and body having interengaging stop surfaces that determine said open position and having a pair of complementally spaced jaws, each individually associated with a separate one of said gripping jaws, said clamping jaws being concurrently cooperable with the gripping jaws to pinch each of the said spaced strap regions when the clamp is in closed position and to release the strap when the clamp is in open position, resiliently yieldable means reacting between said body and clamp normally to bias said clamp to said open position, and means for rocking said clamp to closed position.

6. A tool for tensioning a strap loop having opposite ends threaded through a buckle, said tool comprising an elongated rigid body having a hand grip portion at one end for application of manual force and having a pair of spaced gripping jaws mounted at the other end, each to engage spaced regions of one of said strap ends at 10- cations flanking the buckle with -a ratio of the distance be tween the hand grip portion and the remote one of said gripping jaws to the distance between said gripping jaws substantially determining the mechanical advantage provided by the tool, a pin projecting transversely from said body intermediately of said gripping jaws, a clamp rockable on said pin to swing between an open position and a closed position and having a pair of complementally spaced jaws, each individually associated with a separate one of said gripping jaws, said clamping jaws being concurrently cooperable with the gripping jaws to pinch each of the said spaced strap regions when the clamp is in closed position and to release the strap when the clamp is in open position, and resiliently yieldable means reacting between said body and clamp normally to bias said clamp to one of said positions, said clamp having a rigid handle operable for rocking said clamp to the other of said positions to cooperate with the resiliently yieldable means in enabling repeated gripping and release of the strap end that is being drawn through the buckle.

7. A tool for tensioning a strap loop having opposite strap ends movably threaded through a buckle, said tool comprising an elongated rigid body having a hand grip portion at one end for application of manual force and having a pair of spaced gripping jaws mounted at the other end to engage spaced regions of one of said strap ends at locations flanking the buckle for drawing said one strap end through the buckle by fulcruming the remote one of said jaws against the strap to translate the applied force moment with a mechanical advantage determined substantially by the ratio of the distance between the hand grip portion and the remote one of said gripping jaws to the distance between said gripping jaws, clamping means shiftably mounted on said other end of said body to move between a closed position and an open position and including a separate clamp jaw corresponding to and individually associated with each One of said gripping jaws, each of said clamping jaws being cooperable with its corresponding gripping jaw to pinch the corresponding strap region when the clamping means is in closed position and to release the strap when the clamping means is in open position, and manually operable lever means connected to actuate the clamping means to enable repeated gripping and release of the strap end that is being drawn through the buckle.

8. A tool for tensioning a strap loop having opposite strap ends movably threaded through a strap retaining means, said tool comprising a first member having a pair of spaced gripping jaws mounted at one end to engage spaced regions of one of said strap ends at locations flanking the strap retaining means for drawing said one strap end therethrough, clamping means movably mounted on said first member and positioned to move between a closed position and an open position and including a separate clam-ping jaw being cooperable with its corresponding gripping jaw to pinch the corresponding strap region when the clamping means is in closed position and to release the strap when the clamping means is in open position, and means to actuate the clamping means to enable repeated gripping and release of the strap end that is being drawn through the strap retaining means.

9. A tool for tensioning a strap loop movably threaded through a strap retaining device, said tool comprising a first portion at one end for application of force and a pair of spaced gripping jaws at the other end for engaging spaced regions of the strap at locations flanking the retaining device for drawing the strap therethrough by fulcruming the remote one of said jaws against the strap, a clamp rockable on said tool adapted to swing between an open and a closed position and having a pair of complementally spaced clamping jaws, each individually associated with a separate one of said gripping jaws, said clam-ping jaws being concurrently cooperable with the gripping jaws to pinch each of the said spaced strap regions when the clamp is in closed position and to release the strap when the clamp is in the open position.

10. A strap tensioning tool, and the like, comprising a strap retaining means, means for simultaneously gripping regions of a strap on opposite sides of said strap retaining means, and means for applying a force couple to said strap regions to advance an increment of strap through the strap retaining means whereby one gripping means is used as a fulcrum against its corresponding strap region when the strap is tensioned relative to said strap retaining means.

11. A tool for tensioning a strap loop having opposite strap ends movably threaded through a strap retaining means, said tool comprising an elongated rigid body having a hand grip portion at one end for application of manual force and having a pair of spaced gripping jaws mounted at the other end to engage spaced regions of one of said strap ends at locations flanking the strap retaining means, a clamp rockable on said other end of said body to swing between an open position and a closed position and having a pair of complementally spaced clamping jaws, each individually associated with a separate one of said gripping jaws, said clam-ping jaws being concurrently cooperable with the gripping jaws to pinch each of the said spaced strap regions when the clamp is in closed position and to release the strap when the clamp is in open position, and resiliently yieldable means reacting between said body and clamp normally to bias said clamp to one of said positions.

12. A manually operable strap tensioning tool and the i like comprising a body member, a pair of generally opposed spaced apart jaws on an end portion of said body member and a cutting lip on said end portion generally intermediate of said jaws, and a clamp member rockable and having a shearing edge rocka-ble alongside said shear- I ing extension cooperatively to constitute a shear whereby said tensioning tool is adapted to segment strapping.

14. In strap tensioning apparatus for advancing a strap through a strap retaining means that engages an intermediate bend portion of the strap normally to resist movement of the strap therethrough, the improvement comprising means for simultaneously gripping regions of the strap flanking said return bend portion and spaced from said strap retaining means to assume a generally overlapping spaced apart relation to each other, and means for rotating said gripping means in unison relative to said strap retaining means for applying a force couple to said strap regions to advance an increment of strap through said strap retaining means.

15. The method of advancing a strap endwise through a retainer which frictionally engages an intermediate return bend portion of the strap to resist endwise movement of such portion through the retainer, said method comprising establishing simultaneous clamping engagement individually upon regions of the strap that flank said intermediate portion and that are spaced from said retainer to assume a generally overlapping spaced apart relation to each other, and maintaining said strap regions in generally overlapping spaced relation while applying a force couple through such clamping engagement acting endwise thereon to advance the strap through the retainer.

16. The method of advancing a strap endwise through a retainer which frictionally engages an intermediate return bend portion of the strap to resist endwise movement of such portion through the retainer, said method comprising establishing simultaneous releasable clamping engagement individually upon regions of the strap that flank said intermediate portion and are spaced from said retainer to assume a generally overlapping spaced apart relation to each other, and maintaining said strap regions in generally overlapping spaced relation while applying a force couple through such clamping engagement acting endwise thereon to advance an increment of the strap through the retainer, releasing such clamping engagement and reestablishing clamping engagement at two difierent but similarly spaced strap regions, and applying a force couple through clamping engagement acting endwise on said last named strap regions to advance another increment of strap through the retainer.

17. The method of advancing a strap endwise through a retainer which frictionally engages an intermediate return bend portion of the strap to resist endwise movement of such portion through the retainer, said method comprising establishing simultaneous gripping engagement of spaced grips individually with regions of the strap that flank said intermediate portion and that are spaced from said retainer to assume a generally overlapping spaced apart relation to each other, and maintaining said strap regions in generally overlapping spaced relation while utilizing one grip as a fulcrum against its corresponding strap region and concurrently rotating the spaced grips in'unison relative to the retainer and in the plane of the strap whereby a force couple is applied to said strap regions to advance an increment of strap through said retainer.

References Cited STATES PATENTS UNITED 1,278,069 9/1918 MacDonald 25451 1,304,620 5/1919 Steinkoenig -123.6 1,553,110 9/1925 Rich 140123.5 2,882,934 4/1959 Gerrard 140123.6 3,168,119 7/1965 Schwester et al. l40-123.6

FOREIGN PATENTS 267,020 3/1927 Great Britain.

CHARLES w. LANHAM, Primary Examiner. E. M. COMBS, Assistant Examiner. 

1. A TOOL FOR TENSIONING A STRAP LOOP HAVING OPPOSITE STRAP ENDS MOVABLY THREADED THROUGH A BUCKLE, SAID TOOL COMPRISING AN ELONGATED RIGID BODY HAVING A HAND GRIP PORTION AT ONE END FOR APPLICATION OR MANUAL FORCE AND HAVING A PAIR OF SPACED GRIPPING JAWS MOUNTED AT THE OTHER END TO ENGAGE SPACED REGIONS OF ONE OF SAID STRAPS ENDS AT LOCATIONS FLANKING THE BUCKLE FOR DRAWING SAID ONE STRAP END THROUGH THE BUCKLE BY FULCRUMING THE REMOTE ONE OF SAID JAWS AGAINST THE STRAP TO TRANSLATE THE APPLIED FORCE MOMENT WITH A MECHANICAL ADVANTAGE DETERMINED SUBSTANTIALLY BY THE RATIO OF THE DISTANCE BETWEEN THE HAND GRIP PORTION AND THE REMOTE ONE OF SAID GRIPPING JAWS TO THE DISTANCE BETWEEN SAID GRIPPING JAWS, A CLAMP ROCKABLE ON SAID OTHER END OF SAID BODY TO SWING BETWEEN AN OPEN POSITION AND A CLOSED POSITION AND HAVING A PAIR OF COMPLEMENTALLY SPACED JAWS, EACH INDIVIDUALLY ASSOCIATED WITH A SEPARATE ONE OF SAID GRIPPING JAWS, SAID CLAMPING JAWS BEING CONCURRENTLY COOPERABLE WITH THE GRIPPING JAWS TO PINCH EACH OF THE SAID SPACED STRAP REGIONS WHEN THE CLAMP IS IN CLOSED POSITION AND TO RELEASE THE STRAP WHEN THE CLAMP IS IN OPEN POSITION, RESILIENTLY YIELDABLE MEANS REACTING BETWEEN SAID BODY AND CLAMP NORMALLY TO BIAS SAID CLAMP TO ONE OF SAID POSITIONS, AND MEANS FOR ROCKING SAID CLAMP TO THE OTHER OF SAID POSITIONS. 